1. Field of the Invention
This invention relates generally to clampable gears, end plates for cylinders, and the like, and more particularly is directed towards a new and improved annular plastic gear, end plate, or the like, which is readily clamped onto a shaft at any precise angular position with respect to the shaft.
2. Description of the Prior Art
In a great many machines annular parts such as gears, pulleys, cylinders, rollers, and the like, must be mounted temporarily onto a supporting shaft. In many such machines the precise angular position of the annular part with respect to the shaft is critical to ensure proper operation of the machine such as meshing of parts, for example.
Also, many machines require rather frequent changing of some of their parts. For example, in printing machines a new cylindrical printing plate must be installed each time a printing change is made. This involves removing the cylinder and setting up a new one, then precisely positioning the cylinder on the shaft to ensure proper registration of the print image. Typically, the cylinder is connected to the shaft by means of a set screw extending radially through the hub of the end cap and bearing against the shaft. This technique, while commonly used, is not entirely satisfactory since the set screw tends to dent the shaft slightly and thereby inhibit minor angular adjustments. Other techniques that have been used include keys and keyways, shrink fitting, or slotting the hub of the gear or end cap and using various types of clamps. Slotted hubs require extra machinery operations on the part, while heat shrinking require mounting and demounting devices using electric heat. Similarly, the use of keys necessitates cutting keyways in the shaft and hub while the use of set screws requires drilling and tapping, all of which are expensive, time consuming operations. Thus, none of the measures taken heretofore have been entirely satisfactory from the standpoint of cost, weight, and ease of assembly.
Accordingly, it is an object of the present invention to provide improvements in gears, pulleys, end caps, and the like. Another object of this invention is to provide improved clamping arrangement for gears and the like whereby the gear may be adjusted easily and precisely with respect to the supporting shaft.
Another object of this invention is to provide a low-cost, lightweight plastic gear, pulley, end plate, or the like, that is easily clamped to a shaft and precisely positioned thereon.